Range: Breeds from Alaska and the Pacific Northwest across most of Canada and the Northeast. Winters far north as long as open water is available.

Identification: (Mergus merganser)

Common Merganser is the largest, and has the thickest bill of the three North American mergansers. Male: A rounded greenish-black head (looks black from a distance), with a red-orange bill distinguishes this species. The breast, sides, and secondaries are bright white, with the white underparts sometimes showing a pinkish cast. The back and primaries are black, and the tail is gray. Female: The dark rusty brown head shows a shaggy crest and a clearly demarcated white chin patch. Shows more obvious contrast between the whitish breast and darker rusty brown head than similar female Red-breasted Merganser. Breast, sides, wings, and tail are gray. Flying birds have thin head and neck profile, belly is white, shows a large white wing patch on the secondaries, larger on males. Young birds and males in basic plumage resemble female. Might be mistaken for a loon from a distance.

Length: 56 (cm)
Wingspan: 79 (cm)

Voice:

Usually silent, except for a guttural croaking noise during courtship.

Habitat:

Nests in forests adjacent to lakes and rivers. Winters on large lakes, rivers, and bays. Prefers fresh water.

Field Notes

In regions where these ducks are common breeding birds, females with ducklings join with other females-and-broods until "creches" of dozens of mergansers have formed. These usu assemble in the lee waters of river eddies, at sandbars, and around creek and river confluences; they can persist through summer. The males, in the meantime, having nothing to do with the family, molt into a female-like plumage. The appearance of widely scattered pairs of Common Mergansers along rivers swollen with runoff in March and April, with the streamside trees still bare, is a welcome sign of spring.

On 25 June 2011, I observed and photographed a female swimming with a brood of 17 chicks on the upper reaches of the Metolious River in Central Oregon. According to the Birds of North America (online paid version), the average clutch size is ten eggs.